US2976345A - Insulated electric terminal - Google Patents

Description

March 21, 1961 J. B. WHlTTED INSULATED ELECTRIC TERMINAL Filed 001;. 31, 1957 q a] ,t.

United States Patent INSULATED ELECTRIC TERMINAL John B. Whitted, Kenilworth, 111., assignor to Whitso, Inc., a corporation of Illinois 2 Filed Oct. 31, 1957, Ser. No. 693,693

2 Claims. (Cl. 174-153) This invention relates to an insulated electrical terminal that may be used with an apertured base plate of any desired material. More particularly, the invention provides an improved terminal structure that may be simply made and easily used.

The primary object of this invention is to provide a new and improved insulated electrical terminal structure.

Another object is to provide such a terminal structure comprising but two parts which may be assembled without tools.

Another object is to provide a terminal which may be pushed into an aperture in a base plate and in so doing the terminal structure is in eflect locked in operative position to the base plate.

A further object is to provide a terminal structure of the character described which will meet all standards required of electrical wiring of a nature disclosed.

Other features, objects and advantages of the invention will be apparent from the following description of preferred embodiments illustrated in the accompanying drawings in which:

Figure 1 is a sectional view through a base plate with two terminal structures mounted thereon and shown in section;

Figure 2 is a plan view of the terminal structure shown in the left hand side of Figure 1;

Figure 3 is a transverse sectional view through the terminal of Figure 2, taken on about line 33 of Figure 2;

Figure 4 is a plan view of the terminal structure shown on the right hand side of Figure 1, and

Figure 5 is a transverse sectional view taken substantially along line 5-5 in Figure 4.

All the figures of the drawing are much enlarged since the terminal structures are quite small and the enlargement is only for the purpose of clarity of illustration.

Attempts have been made to form a terminal structure for the purpose of inserting the same in apertures in a base plate permitting wiring to the metal part of the terminal on either side of the plate. Base plates of dielectric material, such as Bakelite, do not have the rigidity to hold a terminal against accidental displacement during installation or later use. It is preferable, therefore, to have a plate of metal which, of course, would be a good electrical conductor.

In general, the present invention provides a new type terminal structure in which a Wire segment comprises the metal part of the terminal and the segment is provided with a carrier body which also serves to insulate the segment from the base plate. As best seen in Figure 1, 'a base plate 6, which may be a steel plate of about 4 thickness or the like, is provided with apertures 7 and 8 of about diameter. On the left hand side of the figure,a push through type terminal 9 is installed in the aperture 7 while on the right hand side, a standoff type terminal 10 is installed in the aperture 8.

Referring first to the terminal 9, it comprises but 2,976,345 Patented Mar. 21, 1961 two parts. The conductor 11 is a wire segment of square design,as best seen in Figure 3. The wire 11 is somewhat sharpened at its end .12 and 13 and extends completely through its housing 14. The housing is a molded nylon plastic body formed with a central round bore 15 and an outer fluted section. The flutes are in pairs, such as a pair 17 (Figure 3) forming a fishtail design in section separated from adjacent fishtail sectional flutes by a square groove 18. This particular form of flute structure has been found quite effective in holding the terminals in a base plate and is more particularly described in my copending application, Serial No. 568,404, filed February 28, 1956, now Patent No. 2,820,209. The end portions 19 and 20 of'the body are tapered, generally, so as to guide the terminal structure into a base plate aperture.

One of the advantages of the present structure is that the terminal conductor and the insulating carrier body may be separately formed. Once the nylon body is molded, the square wire segment may be pushed forceably through the bore 15. As illustrated in Figure 3, the corner portions 21 of the wire become embedded in the wall of the bore thus frictionally locking the body on the wire segment.

In assembling the segment to a base plate, the assembly is pushed into the aperture 7 until the body 14 rests within the aperture. The flutes 1-7 will flatten to allow the body to pass into the aperture. The resiliency of the material makes the flutes expand once through the aperture thus forming a shoulder 22 on the lower side of the plate. In practice, a flute structure about .020" larger than the diameter of the aperture is satisfactory so that a definite shoulder 23 is formed by the flutes on the side of the plate from which the terminal was forced. The flutesrebound or expand outwardly about half the distance required of them to flatten in passing through the orifice. Thus, the flutes 24 on the portion of the body that is passed through the orifice will be about .010" larger than the orifice.

Cooperation between the plate and the body of the terminal may be used to further lock the terminal in place. A notch 25 may be provided in the wire segment about midway within the body so that the nylon material '26 opposite the notch will be forced into it by the compression on the body within the orifice. Other ways of forcing material into a particular configuration in the wire segment may be used. Various shapes, turns, or twists of the wire may provide shoulders such as those on the top and bottom of the notch 25, all of which may aid in locking the parts in their assembly position. Additionally, notches 27 and 28 may be provided in the exposed portions of the wire segment for use and aid in attaching conductors to the segment.

The standoff terminal 10 is similarly formed in that a square wire segment 3-1 is forced into a round bore 32 formed in the body 33. In this form of the terminal, the body may have an enlarged head 34 and a fluted post portion 35 with flutes 36 formed the same as the flutes 17. The terminal segment may have notches 37 and 38 formed for similar purposes as the notches described in the terminal segment 11.

In both of the structures, the body is molded of nylon and then assembled on a wire conductor segment. The assemblage may be accomplished by merely forcing the wire into the round bore molded in the body. A friction fit, similar to the press fit, is accomplished. Considerable force is required to pull the parts apart. Once the terminal is forced into an aperture in the base, more than an ordinary force will be required to move it. The flutes in the body in efiect lock the ternnnal to the base.

Another advantage of the structure is that the insulating housing about the terminal protects the terminal against shorting on the base. Conductors may be attached to the wire segment and in the case of the push-through terminal, simplified wiring is possible since resistors may e maunte on on ide-pf he pla e nd cuitr an the other, and the two will not interfere with each other.

' The terminals are held rigidly upright relative to the base and the body effectively insulates the terminal and holds it in its useable position.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom as some modifications will be obvious to those skilled in the art.

I claim:

1. An insulated electrical terminal, comprising: a two part assembly including a square Wire conductor and an elongated insulating body about the central portion of the conductor, said body being a molded nylon plastic member and having an uninterrupted annular portion throughout its length, said member having a central bore defining the interior of said annular portion and receiving the conductor for frictionally binding the conductor and body together, resiliently yieldable, outwardly extending flutes on the annular portion of said body for binding the body to a base when forced into an aperture in the base smaller than the outermost extent of said flutes and larger than the outer extent of said annular portion, said body having a length to extend on either side of said base holding the conductor in position for use relative to the base and insulating the conductor from the base.

2. An insulated electrical terminal for providing a conductor through an electrically conductive base plate, comprising: a resilient molded nylon body of generally cylindrical configuration and having a round central bore therethrough forming an annular insulating body, an outer fluted surface in the insulating body, a generally square conductor wire extending through the central bore and having its corner portions frictionally gripped in the bore, said fluted surface having outwardly extending flute members extending longitudinally of the body, said flute members being resiliently yieldable to bind the body to the base plate when the assembly of base and conductor wire is forcibly inserted into an aperture therein so that the annular body both mounts the terminal for use and insulates the conductor wire from the base plate.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Erie Resistor Corp. Bulletin ERD 101A, Teflon Insulated Electronic Components, page 7, Erie, Pennsylvania.

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